A second order pvm flux limiter method. Application to magnetohydrodynamics and shallow stratified flows

In this work we propose a second order flux limiter finite volume method, named PVM-2U-FL, that only uses information of the two external waves of the hyperbolic system. This method could be seen as a natural extension of the well known WAF method introduced by Prof. Toro in [21]. We prove that independently of the number of unknowns of the 1D system, it recovers the second order accuracy at regular zones, while in presence of discontinuities, the scheme degenerates to PVM-2U method, which can be seen as an improvement of the HLL method (see [4], [8]). Another interesting property of the method is that it does not need any spectral decomposition of the Jacobian or Roe matrix associated to the flux function. Therefore, it can be easily applied to systems with a large number of unknowns or in situations where no analytical expression of the eigenvalues or eigenvectors are known. In this work, we apply the proposed method to Magnetohydrodynamics and to stratified multilayer flows. Comparison with the twowaves WAF and HLL-MUSCL methods are also presented. The numerical results show that PVM-2U-FL is the most efficient and accurate among them

An MPI-CUDA implementation of an improved Roe method for two-layer shallow water systems

The numerical solution of two-layer shallow water systems is required to simulate accurately stratified fluids, which are ubiquitous in nature: they appear in atmospheric flows, ocean currents, oil spills, . . . Moreover, the implementation of the numerical schemes to solve these models in realistic scenarios imposes huge demands of computing power. In this paper, we tackle the acceleration of these simulations in triangular meshes by exploiting the combined power of several CUDA-enabled GPUs in a GPU cluster. For that purpose, an improvement of a path conservative Roe type finite volume scheme which is specially suitable for GPU implementation is presented, and a distributed implementation of this scheme which uses CUDA and MPI to exploit the potential of a GPU cluster is developed. This implementation overlaps MPI communication with CPU-GPU memory transfers and GPU computation to increase efficiency. Several numerical experiments performed on a cluster of modern CUDA-enabled GPUs show the efficiency of the distributed solver

Characterization and expression of a Pinus radiata putative ortholog to the Arabidopsis SHORT-ROOT gene

We characterized a Pinus radiata D. Don putative ortholog to the Arabidopsis thaliana (L.) Heynh. SHORT-ROOT gene (AtSHR) and analyzed its expression in different organs during vegetative development and in response to exogenous auxin during adventitious rooting. The predicted protein sequence contained domains characteristic of the GRAS protein family and showed a strong similarity to the SHORT-ROOT (SHR) proteins. Quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) and in situ hybridization showed that the gene is predominantly expressed in roots, root primordia and in the cambial region of hypocotyl cuttings. Increased mRNA levels were observed, independently of the presence or absence of exogenous auxin, in the cambial region and rooting competent cells of hypocotyl cuttings within the first 24 h of adventitious rooting, before the activation of cell divisions and the organization of the adventitious root meristem. The expression pattern in organs and during adventitious rooting was similar to that of a Pinus radiata SCARECROW-LIKE (PrSCL1) gene, except that PrSCL1 is induced in response to exogenous auxin. Results suggest that the Pinus radiata SHORT-ROOT (PrSHR) gene has a role in root meristem formation and maintenance and in the cambial region of hypocotyl cuttings.Spanish Ministry of Education and Science (AGL2002-04225-CO2-01 AGR/FOR and AGL2005-07228-CO2-02 AGR/FOR to C.S. and AGL2002-04225-CO2-02 AGR/FOR and AGL2005-07228-CO2-01 AGR/FOR to C.D.-S.) Partially supported by Xunta de Galicia (PGIDIT06PXIB400003PR to C.S.) University of Alcala (UAHCG2006-028 to C.D.-S.).Peer reviewe

Preliminary Study on the Effect of an Early Physical Therapy Intervention after Sentinel Lymph Node Biopsy: A Multicenter Non-Randomized Controlled Trial

Selective sentinel lymph node biopsy (SLNB) represents a minimally invasive surgery in patients with breast cancer. The purpose of this study was to explore the possible effect of an early physiotherapy intervention for the recovery of the upper limb and the surgical scars after SLNB in comparison with usual care. A total of 40 patients were enrolled in either the control group (n = 20) or the experimental group (n = 20). The intervention group performed an early physiotherapy program based on functional exercises, scar manual therapy, and educational tips. The control group received usual care. Shoulder range of motion (ROM), grip strength, upper limb pain and disability (SPADI), scar recovery (POSAS), myofascial adhesions (MAP-BC), quality of life (EORTCQLA-BR-23) and the presence of axillary web syndrome (AWS) and lymphoedema were assessed at baseline and immediately after intervention. A follow-up period of 6 months was performed for lymphoedema surveillance. Between groups significant differences in favor of the intervention were found for ROM (r = 0.43), grip strength (r = 0.32), SPADI (d = 0.45), POSAS (d = 1.28), MAP-BC (d = 1.82) and EORTCQLQ-BR 23 general function subscale (d = 0.37) (p < 0.05 for all variables). Our results suggest that an early physical therapy program seems to be more effective than usual care in women after SLNB. However, results should be interpreted with caution and future randomized trial with a larger sample size is neededThis research was partially supported by ICPFA. Grant number 04722/19P/MA. The funder had no role in the design of the study and collection, analysis, and interpretation of data, and in writing the manuscript. Partial funding for open access charge: Universidad de Málag

Simulation of the carbon dioxide hydrate-water interfacial energy

Hypothesis: Carbon dioxide hydrates are ice-like nonstoichiometric inclusion solid compounds with importance to global climate change, and gas transportation and storage. The thermodynamic and kinetic mechanisms that control carbon dioxide nucleation critically depend on hydrate-water interfacial free energy. Only two independent indirect experiments are available in the literature. Interfacial energies show large uncertainties due to the conditions at which experiments are performed. Under these circumstances, we hypothesize that accurate molecular models for water and carbon dioxide combined with computer simulation tools can offer an alternative but complementary way to estimate interfacial energies at coexistence conditions from a molecular perspective. Calculations: We have evaluated the interfacial free energy of carbon dioxide hydrates at coexistence conditions (three-phase equilibrium or dissociation line) implementing advanced computational methodologies, including the novel Mold Integration methodology. Our calculations are based on the definition of the interfacial free energy, standard statistical thermodynamic techniques, and the use of the most reliable and used molecular models for water (TIP4P/Ice) and carbon dioxide (TraPPE) available in the literature. Findings: We find that simulations provide an interfacial energy value, at coexistence conditions, consistent with the experiments from its thermodynamic definition. Our calculations are reliable since are based on the use of two molecular models that accurately predict: (1) The ice-water interfacial free energy; and (2) the dissociation line of carbon dioxide hydrates. Computer simulation predictions provide alternative but reliable estimates of the carbon dioxide interfacial energy. Our pioneering work demonstrates that is possible to predict interfacial energies of hydrates from a truly computational molecular perspective and opens a new door to the determination of free energies of hydrates.We thank Pedro J. Pérez for the critical reading of the manuscript. We also acknowledge Centro de Supercomputación de Galicia (CESGA, Santiago de Compostela, Spain) and MCIA (Mésocentre de Calcul Intensif Aquitain) of the Universités de Bordeaux and Pau et Pays de l’Adour (France) for providing access to computing facilities. We thank financial support from the Ministerio de Economía, Industria y Competitividad (FIS2017- 89361-C3-1-P), Junta de Andalucía (P20-00363), and Universidad de Huelva (P.O. FEDER UHU-1255522), all three cofinanced by EU FEDER funds. J.A. acknowledges Contrato Predoctoral de Investigación from XIX Plan Propio de Investigación de la Universidad de Huelva and a FPU Grant (Ref. FPU15/03754) from Ministerio de Educación, Cultura y Deporte. J. A., J. M. M., and F. J. B. thankfully acknowledge the computer resources at Magerit and the technical support provided by the Spanish Supercomputing Network (RES) (Project QCM- 2018–2- 0042). Funding for open access charge: Universidad de Huelva / CBU

Fusing Information from Tickets and Alerts to Improve the Incident Resolution Process

In the context of network incident monitoring, alerts are useful notifications that provide IT management staff with information about incidents. They are usually triggered in an automatic manner by network equipment and monitoring systems, thus containing only technical information available to the systems that are generating them. On the other hand, ticketing systems play a different role in this context. Tickets represent the business point of view of incidents. They are usually generated by human intervention and contain enriched semantic information about ongoing and past incidents. In this article, our main hypothesis is that incorporating tickets information into the alert correlation process will be beneficial to the incident resolution life-cycle in terms of accuracy, timing, and overall incident’s description. We propose a methodology to validate this hypothesis and suggest a solution to the main challenges that appear. The proposed correlation approach is based on the time alignment of the events (alerts and tickets) that affect common elements in the network. For this we use real alert and ticket datasets obtained from a large telecommunications network. The results have shown that using ticket information enhances the incident resolution process, mainly by reducing and aggregating a higher percentage of alerts compared with standard alert correlation systems that only use alerts as the main source of information. Finally, we also show the applicability and usability of this model by applying it to a case study where we analyze the performance of the management staff

A Cellular Sudoku Solver

Sudoku is a very popular puzzle which consists on placing several numbers in a squared grid according to some simple rules. In this paper we present an efficient family of P systems which solve sudoku puzzles of any order verifying a specific property. The solution is searched by using a simple human-style method. If the sudoku cannot be solved by using this strategy, the P system detects this drawback and then the computations stops and returns No. Otherwise, the P system encodes the solution and returns Yes in the last computation step.Ministerio de Ciencia e Innovación TIN2008-04487-EMinisterio de Ciencia e Innovación TIN-2009-13192Junta de Andalucía P08-TIC-0420

Source apportionment of ultrafine and fine particles in Huelva industrial city

Comunicación presentada en: 2012 European Aerosol Conference (EAC-2012), B-WG01S2P30, celebrada del 2 al 7 de septiembre de 2012 en Granada

Efficient GPU implementation of a two waves TVD-WAF method for the two-dimensional one layer Shallow Water system on structured meshes.

The numerical solutions of shallow water equations are useful for applications related to geophysical flows that usually take place in large computational domains and could require real time calculation. Therefore, parallel versions of accurate and efficient numerical solvers for high performance platforms are needed to be able to deal with these simulation scenarios in reasonable times. In this paper we present an efficient CUDA implementation of a first and second order HLL methods and a two-waves TVD-WAF one. We propose to write all these methods under a common framework, such as, their CUDA implementations share the same structure. In particular, the reformulation of TVD-WAF numerical flux and the improved definition of the flux limiter allows us to obtain a more robust solver in situations like wet/dry fronts. Finally, some numerical tests are presented showing that the TVD-WAF method is slightly slower that the first order HLL method and two times faster than the second order HLL method, but it provides numerical results almost as accurate as the second order HLL scheme

Ultrafine particle formation in the inland sea breeze airflow in Southwest Europe

Studies on ultrafine particles (diameter < 100nm) and air quality have mostly focused on vehicle exhaust emissions and on new particle formation in "clean" ambient air. Here we present a study focused on the processes contributing to ultrafine particle concentrations in a city (Huelva, SW Spain) placed close to a coastal area where significant anthropogenic emissions of aerosol precursors occur. The overall data analysis shows that two processes predominantly contribute to the number of particles coarser than 2.5 nm: vehicle exhaust emissions and new particle formation due to photo-chemical activity. As typically occurs in urban areas, vehicle exhaust emissions result in high concentrations of black carbon (BC) and particles coarser than 2.5 nm (N) during the morning rush hours. The highest N concentrations were recorded during the 11:00–17:00 h period, under the sea breeze regime, when low BC concentrations were registered and photochemical activity resulted in high O3 levels and in new particle formation in the aerosol precursors' rich inland airflow. In this period, it is estimated that about 80% of the number of particles are linked to sulfur dioxide emissions. The contributions to N of "carbonaceous material and those compounds nucleating/condensing immediately after emission" and of the "new particle formation processes in air masses rich gaseous precursors (e.g. SO2)" were estimated by means of a relatively novel method based on simultaneous measurements of BC and N. A comparison with two recent studies suggests that the daily cycles of "new particle formation" during the inland sea breeze is blowing period seem to be a feature of ultrafine particles in coastal areas of South-west Europe.This study has been carried out within the framework of several research projects: AER-REG (P07-RNM- 03125; Department of Innovation, Science and Enterprise of the Andalusian Autonomous Government), GRACCIE (CSD2007- 00067; Ministry of Science and Innovation of Spain), SIMAND (P07- RNM-02729; Department of Innovation, Science and Enterprise of the Andalusian Autonomous Government) and EPAU (B026/2007/3-10.1; Ministry of Environment of Spain)